Electrical connector apparatuses are widely used in such applications as telecommunications equipment, computers and other digital information systems. The modular nature of most electronic equipment necessitates the incorporation of numerous instances of the use of such electrical connectors. Often, it is desirable to shield the signal-carrying circuits to avoid interference caused by energy generated outside of, as well as inside the system, also known as EMI and RFI, respectively.
Typically, interconnection of individual circuit boards is accomplished using chassis-mounted circuit card connectors or wires. Alternatively, circuit card connectors may be mounted onto a first printed circuit board (PCB) allowing additional PCBs to be plugged into the connectors. As determined by the printed circuit on the first board, each additional board may be interconnected to adjacent boards or to distant boards located several connectors away. In either arrangement, the long interconnections between individual circuit boards reduce system electrical performance by introducing timing and phase shift errors and by compromising the isolation of high frequency analog signals from digital signals.
Stackable connectors provide a convenient way to provide two interface ports to a circuit board (top and bottom) without consuming on the circuit board twice the area required for single connectors. Shielding is provided to prevent any currents from being induced in the individual connectors or contacts between two or more connectors. Shielding between the two connectors of a stacked assembly is most critical in high frequency applications.
Prior art solutions to the above problems include the use of electrical circuit board edge connectors designed to minimize interference between circuit board signals and extraneous signals. Other implementations teach connector elements composed of a strand of metal wire wadded together to form a "button" or wadded wire. The buttons may be used in pairs on opposing ends of an electrical conductive element that is positioned within a hole in a block of insulative material.
In addition to signal isolation concerns, systems incorporating interconnecting signal wires or multiple PCB arrangements are difficult to design for very high inertial applications. Specifically, the interconnecting wires and the mother and daughter boards flex under the high inertial forces developed during periods of high shock, acceleration or deceleration and are therefore subject to failure.
Thus, it can readily be seen that many such electrical connector assemblies are used in conjunction with systems which incorporate PCBs having numerous design requirements. Often it is necessary to also house filter means within the connector assembly. Such filter means are typically implemented using through parts such as through capacitors or through inductors coupled with connector pins. Additionally, numerous applications today require stackable connectors thereby providing convenient interface ports for PCBs thereby eliminating approximately one-half of the connector contacts. Finally, modern manufacturing techniques often dictate solderless connections thereby eliminating the expense and material associated with such applications.
Unfortunately, prior art connector assemblies fail to address the numerous design requirements of many applications thereby limiting the design characteristics of the subject equipment. Accordingly, there is a need for a shielded, stackable, solderless connector/filter apparatus.